Question

What property of a (a) fuse wire (b) filament wire distinguishesit from a normal connecting wire?

Answer 1

Fuse wire :

    It has a low resistance, is soft, and has a low melting point.  So it is connected in series with appliances.  When current is high, the heat generated is enough to melt fuse wire quickly in a fraction of second and break the circuit.

Filament wire:

     It has very high resistance, it is thin, has a very high melting point like 3000 deg. C...  So the filament can heat up to 2000 deg. C, and radiate energy as light energy into the space.